fps gain is no magic formula. we're all using the same materials, or have access to materials others use. i don't think i can match the speed a mathews bow comes w/ from the factory using 452x -which is what they use. why? its not magic. they short strand their strings. they're using 18 strands of 452x for the string. why? to get the ibo speed up. why won't i do it? do you think i want folks talking about my strings the way they do zebra strings? notwithstanding i use better techniques - which i do, all things being equal - if we use the same amount and type of serving - they're string will be faster by 6 fps or so because i use 2 more strands. i can match the speed w/ an 8125 string, but then you have to deal w/ 8125, which is no big deal, but its not set it and forget it like 452x. basically, when you get a sb or a drenalin, or a sbxt - you're getting 5-6 fps of fluff or false speed because they're decreasing string weight by shorting strands. bowtech, for instance, uses 24 strands of 452x - so mathews is using 6 less strands - and still producing slower bows. mathews are great bows, but stranding down to 18 w/ 452x is a cheap speed trick (besides i can tell you by the amt of strings they make it saves a fair bit of money in the long run).
so, to make a long story short - there is no magic in speed - its science, and until a new material is invented, or converted to archery - there are trade-off's to be made, and sacrifices to be made for speed.some i'll make, some i won't.